Method of fractionation



Feb.2s,193o. M. B. COOKE i -1,74s,508

METHOD OF FRACTIONATION Original Filed July 24, 1925 9 ers by means ofA thecup-shaped domes of Patented Feb.` v25, 1930 I UNITED STATES PATENT oFFlcE MAURICE R. COOKE, E PLAINEIELD, .NEW JERSEY, AssIGNoR To THE ATLANTIC REFINING coMPANY, or PHILADELPHIA,` PENNSYLVANIA, A ooRPoRATIoN or original applctionnied 'July 24, 19215,

PENNSYLVANIA Y the art of fractionation, and refers more particularly to a method of treating vapors, such as those of oil, acid, or any type of material, to produce close fractionation or to obtain fractions having a restricted range of boiling points.

My invention resides in a method of the character hereinafter described and claimed. rlhis application is a division of my prior application, Serial No. 45,796, iled July 24, 1925.

As specific examples of some of the forms an apparatus for carrying out my process may take, reference is had to the accompanying drawing, in which Fig. 1 is a sectional side view of a preferred type of tower. Fig. 2 is a sectional 'plan View taken on line 2-2 of Fig. 1, with parts broken away to show various parts. Fig. 3 is a vertical sectional view, partly in elevation, of a modified construction.. Referring to the drawings, at lis shown the usual type of fractionatin'g tower which is preferably cylindrical in form. Vapors are introduced into the tower through a vapor inlet` 2 at the bottom of the tower and discharged at an'upper vapor outlet 3. Within the tower are positioned a plurality of trays 4 equipped with risers 4EL which conduct upwardly the vapors introduced at the bottom of the tower. Surmounting these risers are caps 5 which direct the vapors through ythe several pools of li uid upon the trays 4.

' These caps have pre erably aserrated lower ends, of the downcomer or'overiiow stand through the tops of the Stndpp edge as shown at 6, which serves to break up and more evenly distribute *the vapors whosethe pools below through the overow standfiow is reversed upon discharge from the risthe caps. The 'vaporspassing through the toothed or serrated ledges of the caps, percolatev through the severall pools .of liquid supported upon the trays, the depth of each pool being determined by the height of the upper pipes 7 above the bottoms ofthe respective trays.. With the accumulation of condensate in the pools, the excess material-overflows 7 t0 the METHOD 0F FRACTIONATION Serial No. 45,796.' Divided and this vapplication led March 21, 19,29. Serial No. 348,734.

next'succeeding pools below. Thus the reflux material is gravitated downwardly against the passage of the rising vapors.

` The tops of the caps are shaped to form a lflat surface or grid designated as 8- in the drawings. The tops 'of the capsshownare hexagonal in form in order .that they fit together to form a continuous fiat surface' or grid upon which is placed the packingI material diagrammatically shown at 9. The

tops 8 are perforated by holes 10 which serve to permit a lfree passage of the vapors which 'rise 4'about the serrated edges vof the caps and 4 pass upwardly through the fiat top grid and packing4 material 9 carried thereupon.

In place of the-caps described and shown in Fig. 1, the usual type of bubbler cap 5a may be used as shown in Fig. 3. The bubbler caps serve the purpose of reversislilthe flow of the vapors and causing the sam to percolate through the pools of liquid supported upon the separate trays in the tower. Between the trays is positioned an annular member 11 carried by the angle supports`12. To this member 11 is bolted a circular perforated grid 12 disposed at the opening of member 11. This grid supports the packing material 9 in a manner similar'to the supporting grid formed by the fitted tops 8 of the caps 5j shown in the firsttwo figures of the drawing. It is understood that, if so desired, a grid such as that shown at 12 will be interposed below each of. the bubble tower pools throughout the'v length of lthe tower such asthat partially shown in Fig. 3. OtherwiseLthe construction of the tower is identical inform to the usual type of bubble tower construction having the pools emptying into pipes 7,- while the vapors rise through the successive'tray's by means of risers 4& sur

Fromv the separate pools, ifso desired, liq-` uid condensates or fractions may be drawn oli' through the lines 13, the heaviest .material passing off from the Huid delivery line 14. In actual operation, av bubble tower fractionator is recognized as one ofthe most e cient types of mechanism, as a relatively close @estimation iS attained an@ e esos@ @ariete and intimate contact of the condensate and vapors makes for a uniform final product as' 1 this material along through the successive t-he individual pools.

`to the final product.

pools and overhead to the final condensing zone where it adds undesirable constituents By interposing between the pools a vapor arrester of this character or a similar type which has the de-entraining eHect upon the vapors, and particularly effect-s removal of entraincd liquid from the vapors to cause the same to be separated out and trapped back to the pool below, a much closer fractionation is effected and a more desirable final product produced as Well as the intermediate fractions Which may be `drawn ofi' from A feature of particular importance is that the ref-lux liquid in passing downwardly through the column is not permitted to come into contact with the vapors 4from Whichthe entrained liquid has been removed. This is of particular importance in that if the reflux7 liquid Were permitted to come into contact with the disentrained vapors, re-entrainment would `take place and permit the vapors to pass to the next plate above carrying With them substantial quantities of entrained liquid. A i' It shall be understood that my invention is not limited to specific details as herein set forth, and that my invention comprehends the utilization of equivalentmethods.

What I claim is:

1. In the art of fractionation, the processA which comprises passing vapors through a fractionating column countercurrent to reiiux liquid which forms a se`ries of pools, causing A said vapors in their passageV to contact sucout again bringing them into contact With the liquid so removed, through a vapor zone in the column to a succeeding pool of liquid.

2. In the art of fractionation, the process which comprises passing vapors through a fractionating column countercurrent to reflux liquid which forms a series of pools,

causing said vapors in their passage to contact successively with the pools of liquid, after contacting the vapors with a pool of the liquid causing them to impinge upon surfaces thereby -to remove from the vapors substantially all of the liquid entrained therein, delivering the liquid so removed to a pool of liqquid which the vapors .have theretofore passed, and conducting the vapors, in subs'tantially liquid-free condition and Without again bringing lthem into cont-act With the liquid so removed, through a vapor zone in the fractionating column. J

D 3. In the art of fractionation, the process Which comprises passing vapors* upwardly through a fract-ionating column, passing reflux liquid downwardly through said column, permitting the liquid in its passage downwardly to form a series of pools, causing said vapors in vtheir passage upwardly to contact successively vvith the pools of liquid, causing the vapors after their passage through one of "said pools of liquid to impinge upon surfaces thereby to remove from the vapors substantially all of the liquid 'entrained therein, re-

turning the liquid so removed to the pool of liquid lastl mentioned, conducting the vapors, in substantially liquid-free condition and Without vagain bringing them into contact .with the liquid so removed,'through a vapor zone in the column to the pool of liquid next above, and conducting liquid from the last" mentioned pool to-,the pool below Without permitting such liquid to come into contact With the rising substantially liquid-free vapors.

' MAURICE B. COOKE. 

